A cannula is a thin tube that can be inserted into a patient's vasculature, body cavity or tissue to administer drugs, drain fluids, or insert a surgical instrument. A needle may be used to facilitate the percutaneous delivery of a cannula through the patient's skin so that when placed into its working configuration, the proximal end of the cannula remains outside of the patient's body while the distal end is placed within the intended body lumen, cavity or tissue.
Cannulas may be used for short-term or long-term treatment or therapy. For example, the cannula may remain in place for an extended time period for the long-term delivery of drugs for patients undergoing chemotherapy, for insulin delivery or for the delivery of other fluids via intravenous infusion, drug pumps, a syringe, or the like. Regardless, the use of cannulas may result in inflammation, infection or thrombus formation due to factors such as the presence or introduction of bacteria at the cannula insertion site and unintended blood flow into the cannula. Such inflammation, infection or thrombus formation may cause discomfort or harm to the patient and, in the case of long term drug therapy, may impact therapy effectiveness due to the physiological changes caused by the inflammation at the insertion site.